Growth analysis rapeseed (Brassica napus L.) genotypes in different sowing date under warm and semiarid climate condition in South West of Iran

In Warm and semiarid climate condition alternative cropping in some cases have a negative effect on yield after summer cropping, because of Rapeseed delay planting. By analyzing the growth process, planting date and effective variables on grain yield, Rapeseed can be managed according to its needs. Therefore a split plot experiment in Randomized Complete Block Design with three replications was conducted. Four planting dates (November 6th and 21st. December 6th and 21st) in main plots and four Genotypes (Hyola401, PP401, RGS003 and Option 500) in subplots were studied. The maximum grain yield was belong of Hyola401 hybrid with 2.61 (ton.ha-1) and the minimum grain yield was that of Option 500 variety with 1.51 (ton.ha-1). In general first planting date was superior in physiological index comparing with the other planting dates. Also Hyola401 hybrid, due to the fact that it had a higher leaf area index (3.51), total dry matter (1248.91 g.m -2 ), crop growth rate (21 g.m -2 .day -1 ), net assimilation rate (7 g.m -2 .day -1 ), relative growth rate (0.064 g.g -1 .day -1 ) and maximum grain yield, was seen to be the most adaptable genotype.